Typical loaders include a vehicle body and a canopy mounted on the body for enclosing an operator's seat. The canopy is provided with a front opening that allows the operator to gain access to the operator's seat. Some types of loaders are expected to run over rough terrain, make sudden stops and turns, and are subject to sudden tilting and lurching. A skid steer loader is a type of loader in which the operator often encounters rough ride conditions.
For the operator to be protected safely under the rough ride conditions, need exists for safety devices that can restrain the body of the operator to the seat. The conventional safety devices include a seat bar pivotally mounted to the opposite side walls of the canopy for swing movement about a pivot axis between a raised position and a lowered position. The seat bar remaining in the raised position permits the operator to take or leave the seat through the front opening of the canopy. The operator would be restrained between the seat and the seat bar in case where the seat bar assumes the lowered position. This will keep the operator adhered to the seat even under the rough ride conditions, thus removing the possibility of the operator being thrown from the seat due to the sudden movement of the loader.
In addition to the seat bar, the skid steer loader is provided with a parking brake device which can lock right and left, independently rotatable, front axles against any rotation when the loader is parked and not in service. The conventional parking brake device consists usually of a parking lever manually shiftable between parking and release positions, a rotating disk affixed to the respective one of the right and left front axles and having a plurality of circumferentially disposed notches, a locking pawl releasably engageable with one of the notches of the rotating disk, and a motion delivery mechanism for operatively connecting the parking lever to the locking pawl such that the locking pawl comes into engagement with the notches of the rotating disk as the parking lever is shifted into the parking position.
In the course of driving the skid steer loader referred to above, there may take place such an instance that the parking lever is shifted into the release position by the operator to thereby allow movement of the loader while the seat bar is still in the raised position wherein the operator is not restrained at all. In this instance, the operator would be put in danger and sometimes may be thrown out of the seat particularly when the loader begins to move suddenly. In order to avoid such accident, need has existed for a parking brake device which cooperates with the seat bar in order to bring the loader into a non-parking condition.